我正在尝试创建一个在Android4.2中运行连续语音识别的服务。使用此链接的答案( Android Speech Recognition as a service on Android 4.1 & 4.2 ),我创建了一个从活动运行的服务。我的问题是在handleMessage方法中访问mTarget.mAudioManager
或mTarget.mSpeechRecognizerIntent
时得到空异常。目标(以及从它创建的mTarget对象)是not null,但其中的所有对象都是空的。
我在这里做错了什么?
相关活动代码(从activity调用的静态方法,activityContext是调用此方法的Activity ):
public static void init(Context context)
{
voiceCommandService = new VoiceCommandService();
activityContext = context;
}
public static void startContinuousListening()
{
Intent service = new Intent(activityContext, VoiceCommandService.class);
activityContext.startService(service);
Message msg = new Message();
msg.what = VoiceCommandService.MSG_RECOGNIZER_START_LISTENING;
try
{
voiceCommandService.mServerMessenger.send(msg);
}
catch (RemoteException e)
{
e.printStackTrace();
}
}
服务代码:
public class VoiceCommandService extends Service
{
protected AudioManager mAudioManager;
protected SpeechRecognizer mSpeechRecognizer;
protected Intent mSpeechRecognizerIntent;
protected final Messenger mServerMessenger = new Messenger(new IncomingHandler(this));
protected boolean mIsListening;
protected volatile boolean mIsCountDownOn;
static final int MSG_RECOGNIZER_START_LISTENING = 1;
static final int MSG_RECOGNIZER_CANCEL = 2;
@Override
public void onCreate()
{
super.onCreate();
mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
mSpeechRecognizer = SpeechRecognizer.createSpeechRecognizer(this);
mSpeechRecognizer.setRecognitionListener(new SpeechRecognitionListener());
mSpeechRecognizerIntent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
mSpeechRecognizerIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL,
RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
mSpeechRecognizerIntent.putExtra(RecognizerIntent.EXTRA_CALLING_PACKAGE,
this.getPackageName());
}
protected static class IncomingHandler extends Handler
{
private WeakReference<VoiceCommandService> mtarget;
IncomingHandler(VoiceCommandService target)
{
mtarget = new WeakReference<VoiceCommandService>(target);
}
@Override
public void handleMessage(Message msg)
{
final VoiceCommandService target = mtarget.get();
switch (msg.what)
{
case MSG_RECOGNIZER_START_LISTENING:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
{
// turn off beep sound
target.mAudioManager.setStreamMute(AudioManager.STREAM_SYSTEM, true);
}
if (!target.mIsListening)
{
target.mSpeechRecognizer.startListening(target.mSpeechRecognizerIntent);
target.mIsListening = true;
//Log.d(TAG, "message start listening"); //$NON-NLS-1$
}
break;
case MSG_RECOGNIZER_CANCEL:
target.mSpeechRecognizer.cancel();
target.mIsListening = false;
//Log.d(TAG, "message canceled recognizer"); //$NON-NLS-1$
break;
}
}
}
// Count down timer for Jelly Bean work around
protected CountDownTimer mNoSpeechCountDown = new CountDownTimer(5000, 5000)
{
@Override
public void onTick(long millisUntilFinished)
{
// TODO Auto-generated method stub
}
@Override
public void onFinish()
{
mIsCountDownOn = false;
Message message = Message.obtain(null, MSG_RECOGNIZER_CANCEL);
try
{
mServerMessenger.send(message);
message = Message.obtain(null, MSG_RECOGNIZER_START_LISTENING);
mServerMessenger.send(message);
}
catch (RemoteException e)
{
}
}
};
@Override
public void onDestroy()
{
super.onDestroy();
if (mIsCountDownOn)
{
mNoSpeechCountDown.cancel();
}
if (mSpeechRecognizer != null)
{
mSpeechRecognizer.destroy();
}
}
protected class SpeechRecognitionListener implements RecognitionListener
{
private static final String TAG = "SpeechRecognitionListener";
@Override
public void onBeginningOfSpeech()
{
// speech input will be processed, so there is no need for count down anymore
if (mIsCountDownOn)
{
mIsCountDownOn = false;
mNoSpeechCountDown.cancel();
}
//Log.d(TAG, "onBeginingOfSpeech"); //$NON-NLS-1$
}
@Override
public void onBufferReceived(byte[] buffer)
{
}
@Override
public void onEndOfSpeech()
{
//Log.d(TAG, "onEndOfSpeech"); //$NON-NLS-1$
}
@Override
public void onError(int error)
{
if (mIsCountDownOn)
{
mIsCountDownOn = false;
mNoSpeechCountDown.cancel();
}
mIsListening = false;
Message message = Message.obtain(null, MSG_RECOGNIZER_START_LISTENING);
try
{
mServerMessenger.send(message);
}
catch (RemoteException e)
{
}
//Log.d(TAG, "error = " + error); //$NON-NLS-1$
}
@Override
public void onEvent(int eventType, Bundle params)
{
}
@Override
public void onPartialResults(Bundle partialResults)
{
}
@Override
public void onReadyForSpeech(Bundle params)
{
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
{
mIsCountDownOn = true;
mNoSpeechCountDown.start();
mAudioManager.setStreamMute(AudioManager.STREAM_SYSTEM, false);
}
Log.d(TAG, "onReadyForSpeech"); //$NON-NLS-1$
}
@Override
public void onResults(Bundle results)
{
//Log.d(TAG, "onResults"); //$NON-NLS-1$
}
@Override
public void onRmsChanged(float rmsdB)
{
}
}
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
}
发布于 2013-08-05 11:22:45
MainActivity中的类成员
private int mBindFlag;
private Messenger mServiceMessenger;
在onCreate()
中启动服务
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
Intent service = new Intent(activityContext, VoiceCommandService.class);
activityContext.startService(service);
mBindFlag = Build.VERSION.SDK_INT < Build.VERSION_CODES.ICE_CREAM_SANDWICH ? 0 : Context.BIND_ABOVE_CLIENT;
}
onStart()
中的绑定服务
@Override
protected void onStart()
{
super.onStart();
bindService(new Intent(this, VoiceCommandService.class), mServiceConnection, mBindFlag);
}
@Override
protected void onStop()
{
super.onStop();
if (mServiceMessenger != null)
{
unbindService(mServiceConnection);
mServiceMessenger = null;
}
}
mServiceConnection
成员
private final ServiceConnection mServiceConnection = new ServiceConnection()
{
@Override
public void onServiceConnected(ComponentName name, IBinder service)
{
if (DEBUG) {Log.d(TAG, "onServiceConnected");} //$NON-NLS-1$
mServiceMessenger = new Messenger(service);
Message msg = new Message();
msg.what = VoiceCommandService.MSG_RECOGNIZER_START_LISTENING;
try
{
mServiceMessenger.send(msg);
}
catch (RemoteException e)
{
e.printStackTrace();
}
}
@Override
public void onServiceDisconnected(ComponentName name)
{
if (DEBUG) {Log.d(TAG, "onServiceDisconnected");} //$NON-NLS-1$
mServiceMessenger = null;
}
}; // mServiceConnection
在服务中
@Override
public IBinder onBind(Intent intent)
{
Log.d(TAG, "onBind"); //$NON-NLS-1$
return mServerMessenger.getBinder();
}
发布于 2018-04-18 18:36:07
下面给出了工作示例:
MyService.class
public class MyService extends Service implements SpeechDelegate, Speech.stopDueToDelay {
public static SpeechDelegate delegate;
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
//TODO do something useful
try {
if (VERSION.SDK_INT >= VERSION_CODES.KITKAT) {
((AudioManager) Objects.requireNonNull(
getSystemService(Context.AUDIO_SERVICE))).setStreamMute(AudioManager.STREAM_SYSTEM, true);
}
} catch (Exception e) {
e.printStackTrace();
}
Speech.init(this);
delegate = this;
Speech.getInstance().setListener(this);
if (Speech.getInstance().isListening()) {
Speech.getInstance().stopListening();
} else {
System.setProperty("rx.unsafe-disable", "True");
RxPermissions.getInstance(this).request(permission.RECORD_AUDIO).subscribe(granted -> {
if (granted) { // Always true pre-M
try {
Speech.getInstance().stopTextToSpeech();
Speech.getInstance().startListening(null, this);
} catch (SpeechRecognitionNotAvailable exc) {
//showSpeechNotSupportedDialog();
} catch (GoogleVoiceTypingDisabledException exc) {
//showEnableGoogleVoiceTyping();
}
} else {
Toast.makeText(this, R.string.permission_required, Toast.LENGTH_LONG).show();
}
});
}
return Service.START_STICKY;
}
@Override
public IBinder onBind(Intent intent) {
//TODO for communication return IBinder implementation
return null;
}
@Override
public void onStartOfSpeech() {
}
@Override
public void onSpeechRmsChanged(float value) {
}
@Override
public void onSpeechPartialResults(List<String> results) {
for (String partial : results) {
Log.d("Result", partial+"");
}
}
@Override
public void onSpeechResult(String result) {
Log.d("Result", result+"");
if (!TextUtils.isEmpty(result)) {
Toast.makeText(this, result, Toast.LENGTH_SHORT).show();
}
}
@Override
public void onSpecifiedCommandPronounced(String event) {
try {
if (VERSION.SDK_INT >= VERSION_CODES.KITKAT) {
((AudioManager) Objects.requireNonNull(
getSystemService(Context.AUDIO_SERVICE))).setStreamMute(AudioManager.STREAM_SYSTEM, true);
}
} catch (Exception e) {
e.printStackTrace();
}
if (Speech.getInstance().isListening()) {
Speech.getInstance().stopListening();
} else {
RxPermissions.getInstance(this).request(permission.RECORD_AUDIO).subscribe(granted -> {
if (granted) { // Always true pre-M
try {
Speech.getInstance().stopTextToSpeech();
Speech.getInstance().startListening(null, this);
} catch (SpeechRecognitionNotAvailable exc) {
//showSpeechNotSupportedDialog();
} catch (GoogleVoiceTypingDisabledException exc) {
//showEnableGoogleVoiceTyping();
}
} else {
Toast.makeText(this, R.string.permission_required, Toast.LENGTH_LONG).show();
}
});
}
}
@Override
public void onTaskRemoved(Intent rootIntent) {
//Restarting the service if it is removed.
PendingIntent service =
PendingIntent.getService(getApplicationContext(), new Random().nextInt(),
new Intent(getApplicationContext(), MyService.class), PendingIntent.FLAG_ONE_SHOT);
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
assert alarmManager != null;
alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, 1000, service);
super.onTaskRemoved(rootIntent);
}
}
有关详细信息,请参见
希望这能在未来对某些人有所帮助。
https://stackoverflow.com/questions/18039429
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